Jennifer Kennedy, University of Maryland College Park, College Park, MD, United States, George C Hurtt, University of Maryland, Department of Geographical Sciences, College Park, MD, United States and Xin-Zhong Liang, College of Atmospheric Science, Nanjing University of Information Science and Technology, Nanjing, China; Department of Atmospheric & Oceanic Science, University of Maryland at College Park, USA, Nanjing, China